Construction Of CuInS₂ Quantum Dots Composite And Study On Photodegradation Of 2,4-dichlorophenol

In China,the annual discharge of wastewater is as high as tens of billions of tons,and organic pollutants in water have become one of the main sources of pollution.Because 2,4-dichlorophenol?2,4-DCP?is a kind of important organic chemical raw material,it owns a pivotal position in the industrial production field.However,2,4-DCP is potentially dangerous to the environment and organisms,and the high stability of the chlorine-carbon bond makes it difficult to biodegrade,bringing a lasting effect,including causing dermatitis,anemia,acne,cancer,etc.In order to remove of 2,4-DCP organic pollutants in water,a variety of technical methods have been developed in the past researches,including wet oxidation,activated carbon adsorption,biodegradation,photocatalytic degradation,etc.However,semiconductor photocatalysis technology has been widely concerned by scientific researchers because of its advantages of simple operation,low cost,high efficiency and fast.CuInS₂ as an important class of ternary metal sulfides,CuInS₂ quantum dots with a light absorption coefficient of up to 10^-55 cm^-11 have unique optical properties.Although CuInS₂ quantum dots have good sunlight absorption,they still exist the disadvantages of high photogenerated carrier recombination rate,poor adsorption capacity,and difficult recovery,which limit the practical application range.Therefore,we adopt a variety of ways to modify the catalyst to improve the photocatalytic performance.In this subject,CuInS₂ quantum dots were obtained by hydrothermal method.At the same time,CuInS₂ quantum dots were modified with TiO₂ nanorods to construct CuInS₂/TiO₂ composite photocatalysts with good photocatalytic performance.secondly,CuInS₂ quantum dots were grown on hydrotalcite flakes to form CuInS₂/NiAl-LDH composite light catalyst.Finally,CuInS₂/BiOI composite photocatalysts were prepared by introducing BiOI flower balls modified CuInS₂quantum dots.The content of the topic is as follows:1.A new type of photocatalyst was successfully constructed by hydrothermal method.The photocatalysts contained a direct Z-scheme CuInS₂/TiO₂ heterojunction.Through experimental analysis,it can be seen that when the mass ratio of CuInS₂quantum dots reached 9.0%,the photocatalytics degradation efficiency to2,4-dichlorophenol reached 86.6%within 120 min.Moreover,the Z-scheme mechanism significantly reduced the recombination rate of photogenerated electron-hole pairs while retaining the redox activity of the catalyst.At the same time,it was further analyzed by using laser Raman spectroscopy?Raman?,X-ray energy spectrometer?EDS?,transmission electron microscope?TEM?,specific surface area and porosity analyzer.2.Using hydrothermal method,NiAl-LDH flakes of different sizes were prepared at different temperatures.When the temperature was 160?,NiAl-LDH hexagonal flakes with the largest specific surface area were obtained.CuInS₂ was modified on NiAl-LDH sheet,and 0D/2D CuInS₂/NiAl-LDH heterojunction photocatalysts were designed and synthesized.CuInS₂ was modified onto NiAl-LDH to design and synthesize 0D/2D CuInS₂/NiAl-LDH heterojunction photocatalysts.Through the combination with NiAl-LDH,the specific surface area of the catalyst was further increased,and the adsorption capacity of the photocatalyst was improved.The results showed that when the mass ratio of CuInS₂ quantum dots reached 17.5%,and the photocatalytic degradation efficiency of 2,4-dichlorophenol reached 84.5%in120 min.3.The CuInS₂/BiOI flower ball composite photocatalyst was successfully constructed by in-situ growth method.CuInS₂ quantum dots were uniformly embedded into the petals of BiOI flower balls,which can greatly improve the recycling rate.The results showed that the photocatalytic degradation efficiency of2,4-dichlorophenol reached 78.2%within 150 min when the mass ratio of CuInS₂quantum dots reached 30%.